TAMPA — Reggie Jackson was standing a foot inside the Yankees’ clubhouse Monday morning at George M. Steinbrenner Field, holding court with three reporters, when Aaron Judge filled up the doorway.

After Judge and the Hall of Famer traded hellos, the 6-foot-7, 255-pound Judge moved to his locker.

Jackson, who spent time with Judge last summer when the right fielder played for Double-A Trenton, believes he will be a productive big leaguer for the Yankees. Jackson was asked if he were that size as a player, what would 563 homers have been.

“Nine-sixty-three,’’ Jackson answered without a doubt.

Jackson, who will be 70 in May, is 13th on the all-time home run list. The 6-foot Jackson said he weighs 203 pounds, but the final year he played (1987), he was about 20 pounds heavier.

Had Jackson swatted 963 homers, Barry Bonds’ 762 would be good for only second place on the all-time list.

Like Jackson, who is the career leader in strikeouts with 2,597, Judge has big power and is prone to the whiffs. In two minor league seasons, Judge has struck out 275 times with 266 hits and 37 homers in 945 at-bats.

Nathan Eovaldi said the left groin problem that kept him off a pitching mound recently and surfaced during a conditioning drill last week is being treated carefully because it’s early in spring training.

“It feels fine, just being really cautious about it,’’ said Eovaldi, who is slated to throw a bullpen session Wednesday. “I am doing everything. If this was during the season, it would be fine.’’